Not sure I agree at all with the assessment of the tone of the article. It seems pretty straightforward reporting.

Relatedly, the US has 30 times as many homeless. Given the same costs as Finland's solution, it would take two Trump Walls to implement in America.

Yes, the United States is big, but there are plenty of problems that scale up linearly, so they should be no more difficult for a big country with big resources to implement than a small country with small resources. If (for example) US homelessness cost the country two Trump Walls every five years, then the significant up front investment to give everybody a house is still worth it.

I have read a lost of suggestions that things that work elsewhere in the world can't work in America (gun control, metric system, etc) "just because", and I think that it is just a form of (reverse?) American Exceptionalism.

The true reason things get done or not done are always political, just like my country and everywhere else in the world.

Just to interject my personal opinion into my observation: housing the homeless is worth more than several Trump Walls. Maybe another way of framing it is as costing an eighth of Trump's military budget increase (which, of course, will be approved, of course, because, of course, foreverwar, of course).

I have read a lost of suggestions that things that work elsewhere in the world can't work in America (gun control, metric system, etc) "just because", and I think that it is just a form of (reverse?) American Exceptionalism.

America is, indeed, exceptional in many ways including its heterogeneity, and its attendant racism. Xenophobia is at the root of why Big Ideas are harder in the US: For me, but not for thee. History has shown that social safety net programs do not get fairly distributed. However, I think that doesn't mean not try.

Then again, many of the people saying "it works elsewhere but not here" about success stories will turn right around and "if we Socialism, we'll literally become Venezuela!"

Significant upfront investments won't get you reelected when the voting public has the attention span of a stoned goldfish.

Finland has a functional social safety net, though; the US very much does not. So not only would the US have to spend more to house the homeless, they'd also have to start providing free college tuition, universal healthcare, and so on. You know, all the things civilized countries already do. Of course the long-term benefit would be fewer people in need of housing...

(But the poor billionaires! And that mean nasty 70% marginal tax rate!)

Is this an example of the perfect being the enemy of the good? Are we waiting for everything to perfectly align before pulling the trigger?

This could be a matter of triage: address the most harmful situation first and move on from there. But it also could be a matter of first steps: Just do something. If housing homeless, regardless of healthcare or education or etc., is a simple, helpful step, then just do it. Tackle another problem next. It would be a matter of a little pain, followed by tangible, demonstrable results, shoring up the next plan toward social justice.

The problem is that if one jurisdiction tries to solve the problem, it just encourages the homeless from elsewhere to go there.

The Christian Science Monitor isn't really a Christian outlet, it was just founded by a weirdo:

Despite its name, the Monitor is not a religious-themed paper, and does not promote the doctrine of its patron church. However, at its founder Eddy's request, a daily religious article has appeared in every issue of the Monitor.
....
The Monitor's inception was, in part, a response by its founder Mary Baker Eddy to the journalism of her day, which relentlessly covered the sensations and scandals surrounding her new religion with varying degrees of accuracy. In addition, Joseph Pulitzer's New York World was consistently critical of Eddy, and this, along with a derogatory article in McClure's, furthered Eddy's decision to found her own media outlet.[5] Eddy also required the inclusion of "Christian Science" in the paper's name, over initial opposition by some of her advisors who thought the religious reference might repel a secular audience.

See, another trigger-happy comment– sorry!

You might be right. I often feel that reporting on foreign social politics is missing out on local factors, so this was probably more of a reflex.

It's easy to solve the homeless problem in Finland. They don't usually last more than one winter.

Nah, our homeless are a tougher breed. I recall hearing a story about the homeless in the UK and how they freeze to death when the temperature drops close to 0 Celsius. Nothing like that 'round these parts.